Generally, a switched-mode power supply receives a DC voltage as input, coming from a DC network. It is also possible to configure the switched-mode power supply to be supplied by a DC voltage resulting from rectification of an AC voltage. A supply may be subjected to a micro-outage when it is deprived of an energy source for a short time. In order to protect the supply from micro-outages and to enable it to continue to operate (that is to say to continue to supply its output voltage or voltages) during the network micro-outage, protection architectures may be implemented.
Document FR 2 983 005 discloses a switched-mode power supply architecture as represented by the circuit of FIG. 1.
Input terminals 100, 101 receive a DC input voltage to convert from a DC electrical network (or from a rectified AC network). A conversion module 102 (which may comprise a plurality of converters) regulates that input DC voltage and provides regulated output voltages on the output terminals 103. In order to protect the switched-mode power supply, an energy store module 104 is connected to the terminals of the conversion module.
A control circuit 105 (for example a NOT gate) controls a switch 106 (for example a MOSFET transistor) connected in parallel with a diode 107. All the components 105, 106 and 107 form part of a module 108 for connecting and disconnecting the supply of the electrical network providing the DC voltage input.
The storage module is charged and discharged by a charging and discharging module 109. The module 109 comprises a circuit of “buck-boost” type (a circuit of “inverter” type).
Two switching modules 110, 111 are connected in parallel to the energy store module. Each switching module comprises a switch (for example a MOSFET transistor) connected in parallel with a diode. The switches are controlled by a charging and discharging management module 112.
The module 111 is connected between the storage module 104 and the module 110. The module 110 is connected between the module 111 and the conversion module 102.
An inductor 113 is connected between the input terminal 101 and the connection point of the switching modules 110 and 111.
The voltage of the input terminal 101, which is common to the input electrical network, to the charging and discharging module 109 and to the energy store module 104 is taken as a reference. This node of the circuit is taken as the ground (or “cold point”) for the circuit. The cold point of an electrical supply corresponds to its negative terminal or to the ground of the circuit of which it forms part. In contrast, the “hot point” of the supply corresponds to its positive terminal.
When a micro-outage occurs, an architecture according to document FR 2 983 005 makes it possible to have, at the input of the conversion module, a regulated DC voltage while the energy store stored in the storage module is used, independently of the voltage at the terminals of the storage module.
Furthermore, the conversion module is always connected (via the charging and discharging module) to the energy store. The conversion module is thus not disturbed at the start of the micro-outage, when it stops using the energy of the network to begin to use that of the storage module. The same applies at the end of the micro-outage.
Furthermore, the charging and discharging module only generates significant losses during the period of the initial charging of the storage module and during the micro-outage.
The architecture according to document FR 2 983 005 thus provides numerous advantages relative to the architectures of the prior art constituted by series and parallel structures presented in that same document.
The architecture disclosed herein has been developed by making improvements thereto, in particular by providing high freedom of implementation.